A few weeks ago, I started a series on how to get rid of ants from your home for good. Part 1 explains why I am writing about this here, now. [link]

First, the disclaimer: I am no expert on insect behavior. I am first to admit that I have never read a scientific book about ants. I am a good problem solver; all I have to share here is what I learned from observation and dogged trial and error. The solution has held up for two decades, all observations since have been consistent. Other people in my life have used this solution to good effect. My apologies in advance for the inexact terminology. And as always, I cannot guarantee results, my intent is just to share what worked for me – and most importantly – why.

About twenty years ago, I lived on the second floor of an old apartment building. Not long after I moved in, a thick stream of ants established a trail through my bathroom, from a crack in the window above the bathtub, down the tile wall, across the length of the old vinyl flooring, to the trash can by the door.

Wiping up the ants and moving the trash can a few feet did nothing. The ants followed their old trail inside, and quickly established a new trail to the new location of the trash can. The ants seemed undeterred by threat of death to some of their numbers – more kept coming in. Leaving some dead ants around seemed only to attract more ants to take them away.

Meticulous cleaning and keeping the trash empty didn’t work; the minute a damp tissue or a little used dental floss hit the can, ants swarmed it. Soon the ants branched out from the trash can, finding their way into the shampoo, my toothbrush, the sink, the toilet, everything. Yuck. This is when I discovered that ants do indeed bite.

I’m sure I tried a number of hack deterrents and folk remedies that failed to work, long forgotten. Poison in my apartment wasn’t a good solution for obvious reasons, but I think I tried it anyway out of desperation. So we’ll skip to the point where I get to my wits end.

Feyman was an interesting, funny guy with diverse interests. He conducted his own amateur science experiments; at one point, the book described his fascination with ants and their dependence on scent trails.

I tried unsuccessfully to duplicate what Feyman described in his book – if I remember correctly, getting the ants to leave a trail on a piece of paper, then turning the paper around. I had a vague idea of maybe redirecting the ants outside. The ants had such a strong attraction to that trail on my floor, they simply treated the paper as an obstacle and went around it, picking up their original trail on the other side.

So I decided to see what would happen if I obliterated their scent trails. This turned out to be harder than I expected.

I have probably forgotten many of the things I tried, but I do remember trying to wipe up the trails with straight bleach, Lysol disinfectant spray, Ivory dishwashing liquid, Windex, Comet, (probably) Bon Ami, Formula 409, isopropyl alcohol, Lysol household cleaner, lemon juice, vinegar, (probably) Pine-Sol… And of course I washed off each of these chemicals with what I now know is dishwashing detergent and rinsed well before trying another.

Nothing really worked. I could wipe up the existing ants and try to clean up the trail, but the ants seemed to be able to pick up the scent and re-establish the trail in short order. Scrubbing the room spotless sometimes gave me a short breather from the onslaught, but such spotlessness is impossible to maintain, so the ants quickly returned.

I have found this behavior consistent over time: when ants have invaded kitchens or other rooms for food, they will usually disappear for awhile after a cleaning, but reappear in strength the moment a crumb hits the floor, it seems.

Years after this, a friend – an expert on insects – explained to me just how dependent ants are on scent. He told me that in experiments where researchers painted some ants with the scent given off by dead ants, worker ants would remove the dead-ant-scented ants from the colony AS IF THEY WERE DEAD, even though they were clearly moving. When the marked ants tried to return, the other ants simply kept removing them until the marked ants eventually gave up. (This may very well be from E.O. Wilson’s work or book, though I am just guessing based on some web pages I saw recently.)

For some reason, the ants in my apartment were willing to face an ongoing threat of death, the inconvenience of ever-changing obstacles, and all manner of attempts on their scents trails, and still they kept coming in as if pushed by an inexorable force and following some kind of indelible trail.

I discovered the answer by pure luck. In my attempts to clean up the trail – silly as I felt after trying so many other cleaners – I sprayed down my foaming tub cleaner, Lysol Basin Tub and Tile Cleaner, and wiped up every surface with it. Then an odd thing happened. The ants emerged from their entry point at the window, and scattered where I had cleaned the tile. But this time, they did not regroup. The seemed unable to re-establish the trail, totally lost.

After awhile, I used the Basin Tub and Tile Cleaner to wipe the “confused” ones up. I did this a few times over a couple of days, in the same way I had used other cleaners to repeatedly wipe up the ants. Only this time, the ants behaved differently, never seemed to find a trail. They seemed slow, even tentative when they entered. They seemed to lose all sense of direction. After a couple of days, they disappeared completely. And they never came back.

It wasn’t a fluke. I have repeated this many times over the years, in different apartments and homes, in different locations, with different kinds of ants. Always, the same thing happens. This cleaner really does seem to completely obliterate the ant scent trail, and it seems as if the ants just cannot cope with that.

What makes this different than merely cleaning up their food source, is that it seems as if the ants leave some kind of warning scent to never return. At times when I have merely cleaned up, ants may disappear for awhile, but they keep sending in scouts, they keep returning eventually. This is why ant baits have never worked for me – nevermind that one cannot leave them out in households with small children – the ants may take the bait and kill that existing colony, but in my experience, they usually return IN THE SAME PLACE, as if there is a lasting scent directing them inside to try again for some once-successful food source.

In one home where I experimented with bait, the ants returned in strength after a year, only this time they wouldn’t take the bait! Initially I had not wanted to use the Lysol Basin Tub and Tile Cleaner on some of the surfaces, but when I did, again they disappeared forever and never returned, not even after years.

What’s interesting here is that it doesn’t appear to be the residue of the cleaner that does this – especially now with the eczema, I usually wash off the cleaner with soap after using it, because it is a detergent product – but it appears to work just as well. (And the soap itself is not enough to produce this effect.)

Even better, the ants just don’t come back, no matter how lax I become about leaving out sugary food or other surefire ant attractions.

One time, when I had a very major incursion in a laundry room, the widest trail of ants I had ever seen indoors (over an inch wide and fairly densely packed), I had to spray down the Lysol Basin Tub and Tile Cleaner and leave it down for a few hours. I never thought it would work, yet again the ants seemed just unable to cope with that. Again, they disappeared, and never came back.

Why do I think this is the result of a warning scent? Well, several reasons. I have observed equivalent behavior with a different kind of insurmountable ant obstacle – stay tuned for Part 3, which I will post soon, along with my “method” for cleaning up the ants forever.

Note: Unfortunately, Lysol Basin Tub and Tile Cleaner seems to be disappearing from store shelves. The customer service rep told me that they have repackaged it as Lysol Bathroom Cleaner, but the fragrance has been changed. Since I cannot tell what it is about this cleaner that makes it different – after all, regular Lysol spray disinfectant and the general Lysol household cleaner did not work for this – and it doesn’t appear to be just the active ingredient, I cannot tell if the fragrance change will make it less effective. I have a stock of the old stuff, but I tried to order more online and received the Bathroom Cleaner despite ordering the Basin Tub and Tile Cleaner. The bathroom cleaner might work, it might not. More about this soon.